low fuel trim code

[emeracing]

ok i have 95 eagle talon tsi. i just replaced the exhaust manifold and exhaust housing side of turbo and spark plug wires and fuel pump and now all of a sudden im getting a low fuel trim code and i cant figure out y i replaced the IAC brand new and still same thing and everything i replaced is new OEM replacement parts so i need some ideas please

 

[dustyboner]

low, like a negative fuel trim (the ecu is pulling fuel), right? Maybe you just have way better fuel flow with the new pump. What was the code, P0170 ?

 

[emeracing]

here is the scan i have

 

[dustyboner]

You must be logged in to view this image or video.

 

[emeracing]

hmmmmmm i wondring if the heated oxi sen is bad because we had to cut the bolts off the down pipe with the o2 in it

 

[boostdawd]

How old is the O2 sensor?

 

[boostdawd]

I had this happen to me when Arizona sneakily changed E85 to E54 without labeling it or telling anyone. Luckily this forum brought it to my attention.

 

[emeracing]

here is my scans and yes my car is not fully warm

 

[emeracing]

for all i know its the stock one still but i would think i would get a o2 code though

 

[dustyboner]

let it hit operating temp so it will go into closed loop. when the car goes into closed loop the O2 voltage should be constantly switching from hi to low. if it doesn't switch and just stays high or low or in the middle, or it switches to slow it should throw a code. it wont always but if your lucky.

 

[emeracing]

let it hit operating temp so it will go into closed loop. when the car goes into closed loop the O2 voltage should be constantly switching from hi to low. if it doesn't switch and just stays high or low or in the middle, or it switches to slow it should throw a code. it wont always but if your lucky.

you can see where it warmed up and still didnt close loop i saw it close loop once as warming but went back to open and stayed

 

[wrencher]

Well I might start to suspect that o2 sensor or a large exhaust/air leak .
But you'd likely hear the later.
Have over 25 years of working on vehicles a handful of o2's give up the ghost after being removed/reinstalled.

 

[pauleyman]

I concur. O2 sensor is suspect. Log a graph and if doesnt cycle diagnose that sensor/circuit.